Definitely worth it!

TTP is a rigorous course that delves deep into making sure that you understand all of the fundamentals. I thought I was pretty good at maths but after taking the TTP diagnostic test I realised my knowledge was very rusty. TTP sets out all the topics in a nice understandable layout, and constantly provides numerous mini exercises throughout each chapter to make sure you have understood the material you are reading, each with their own valuable video explanation. The quality of the questions is extremely high, which means you get used to the hard questions you will encounter on the GMAT. I studied the material for 3/4 months and went from a 590 to a 710! Highly recommend.